Valve mechanism for rock drills



Juiy 15, 1930. w. A. SMITH. JR

VALVE IECHANISI FOR ROCK DRILLS Filed Sept. 7, 1928 INVENTOR. Wilia mjlmi UfJI:

HIS RNEY.

Fatente July 15, 1930 I LIL-1AM A..- SMITH, J'E., OE PHILLIPSBURG, NEW JERSEY, ASSIGNOR TO INGERSOLL- D COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY VALVE MECHANISM FOR ROCK DRILLS a Application filed September This invention relates to fluid actuated rock drills, but more particularly to a valve mechanismfor distributing the pressure fluid to the ends of the rock drill cylinder.

a sturdy and reliable valve mechanism capable of a rapid action for distributing the pressure fluid to the cylinder and to simplify and lighten the structure of valves of this type.

Other objects will be in part obvious and in part pointed out hereinafter.

In' the accompanying drawings illustrating the invention and in which similar reference characters refer to similar parts, 4

Figure 1 is a sectional elevation of a rock drill equipped with a valve mechanism constructed in accordance with the practice of the invention,

Figure 2 is a transverse view taken-through 2e Figurel on the line 2--2 looking in the direction indicated by the arrows, and v Figure 3 is a similar view of a modified term of the invention.

' Referring to the drawings, A represents a 25 rock drill comprising a cylinder Bhaving in this instance a pair of free exhaust ports 0 for conveying exhaust fluid from a piston chamber D in the cylinder B. The cylinder B is provided with a reciprocatory hammer 3c piston E having a forward fluted extension F which extends slidably through a bo'reG "of a front cylinder washer H inserted in'the front end of the cylinder to form a closure for the piston chamber D.

3 5 In the rearward end of the cyhnder is a bore J to accommodate suitable rotation.

mechanism for inducing a step by step rotation of the working implement '(not shown). The rotation mechanism comprises .the usual rotation ratchet K, which may be -..suitably secured in the bore J, and a rifle bar which interlocks slidably with the hammer piston E in a well known manner. The rifle bar L has the usual head 0 which lies in the same transverse plane as the rotation ratchet K and carries spring pressed pawls P adapted to engage teeth Q, of the rotation ratchet for holding the rifle bar stationary during one of the strokes of the piston E, preferably as during the rearward stroke of the piston.

The objects of the invention are to obtain,

7, 1928. Serial No. 304,561.

Disposed at the rearward end of the cylinder B is a hack head R which seats in this instance on the rotation ratchet K and has a throttle'valve chamber S to rotatably receive a throttle valve T. The throttle valve T has a chamber U which may be in constant communication with a source of pressure fluid supply. In the wall of the throttle valve T is a port- V which, in the open position of the throttle valve, registers with a passage W in the back head leading to a su ply reservoir X in the forward end of said ack head.

In accordance with the present invention, valve mechanism is provided for effecting the distribution of pressure fluid to the ends of the piston chamber D for actuating the piston E. The valve mechanism is designated generally by Y and comprises apair of plates Z and b. The plate I) is disposed in the forward end of the bore J and has a rearwardly extending annular flange 0 which is in body engagement at its outer periphery with the bore J. The plate Z interposed between the plate 6 and the rotation ratchet K is likewise in body engagement with the cylinder D whereby said plate, like the plate 6,

is centralized in the cylinder. 7

On the plate Z is a forwardly extending projection d which may seat on the plate 5 and is of smaller diameter than the flange 0 to form an annular valve chamber 6 between the outer surface f of the projection d and the inner surface 9 of the flange c.

The valve chamber e is constantly supplied with pressurefluid which is conveyed theretothrough supply passages 7:. leading from the supply reservoir X to the valve chamber and said supply passages it are preferably formed in the rotation ratchet K and in the plate Z."

In the plate Z are formed rearward inlet passages h which open at their inlet ends j in the valve chamber 6 and at their outlet openings kin the rearward end of the piston passage 0 through an annular groove 9 preferably formed in the outer surface of the flange c.

The surfaces f and g of the projection d and the flange c are of cylindrical formation and these surfaces constitute valve seats for distributing valves 1 which control the admission of pressure fluid from the valve chamber e into the inlet passages h and o. The valves 1', of which four are shown for the purpose of illustrating the invention, are in the form of thin arcuate strips and have in this in stance apertures a near their ends to receive pins t preferably seated in the projection d for limiting endwise movement of the valves 1'. The valves 1 are adapted to reciprocate transversely of the valve chamber e and are suitably spaced with respect to each other to avoid contact between said valves.

In order to constantly assure the presence of pressure fluid throughout the valvechest e, the pro'ection d and the flange 0 are provided wit grooves u and '0 which lie above the surfaces f andg so that a portion of both sides of the uppermost ends of the valves 1' may be constantly exposed to live pressure fluid. Similarly grooves w and w are formed in the projection d and the flange -c respectively beneath the surfaces f and g to expose similar areas of the. lowermost portions of the valves r constantly to pressure fluid.

In the construction shown, the valves r are of such proportions as to overlie 'both the grooves above and below the surfaces f and g. Pressure fluid may, however, be constantly present in these grooves irrespective of the position of the valve since, as will be observed, considerable space exists between the adjacent ends of the valves through which pressure fluid may pass into the grooves adJacent the surface against which the valves are seated.

The operation of the device is as follows: With the throttle valve T in the open position illustrated, pressure fluid will flow through the passage W and h into the valve chamber e. With the valves '1' in position to cover the inlet ports p, pressure fluid will flow through the valve chamber e, thence through the rearward inlet passages h into the rearward end of the piston chamber D to impel the piston forwardly in the direction of the working implement. As the pisto n E proceeds in a forwardly direction, it will cover the exhaust ports C and the air in the front end of the piston chamber D will be compressed. Compression will then flow through the inlet passage 0 through the groove (1 and the inlet ports p to act against the outer surfaces of the valves 1' over an area equal to the cross-sectional area of the inlet ports 1?. Atthe same time the upper and lower portions of the outer surface of the valves 1' equal in area to the height of the grooves o and a: will be exposed to live are uncovered, the pressure on the inner surfaces of the valves 7' will drop abruptly and compression and live air acting against the outer surfaces of the valves w1ll throw the valves 1- against the surface f of the projection d.

After the valves r have thus been actuated pressure fluid will flow from the valve chamher 6 through the inlet ports p into the groove 9 thence through the inlet passage 0 into the front end of the piston chamber D to return the piston to its initial position. 'After the piston E covers the exhaust ports C during the rearward stroke of said piston, the air compressedin the rearward end of'the piston chamber D will flow through the rearward inlet passages h to act against the inner surfaces of the valves 1' to augment the live pressure in the grooves u and w'acting against the innersurfaces of the valves 1'. When the piston E overruns the exhaust ports C, the pressure acting against the outer surface of the valves 1' will drop and the compression and live air acting against the inner surfaces of the valves rwill then again actuate the. valves r outwardly against the seating surface 9 of the flange 0, thus completin' the c cle of operation.

In t e mo ified form of the invention. il-

lustrated in Figure 3, means are interposed between the adjacent ends of the valves for limiting longitudinal movement of the valves in the valve chamber 6. Such means preferably consist of separate areuate plates y which may extend from the surface 7 of the projection d to the surface 9 of the flange c. The plates y may be secured to the valve chest Z in any suitable manner, pins 2 being used in this instance for this purpose. The pins 2 are seated in the projection d and extend through apertures 2 in the plates 3 The spaces 3 between the plates 3 are pref erably somewhat longer than the length of the valves 1' disposed in said s aces 3.

As will be observed, the va ves 1- are' capable of a certain degree of endwise movement and this is not objectionable since the sha e of the valves 7* conform closely to the sur aces f and 9 against which the valves are adapted to seat. The operation of this modification differs in no essential respect from that described in connection with the previous modification.

I claim:

1. In a fluid actuated rock drill, the combination of a cylinder and a piston, an exhaust port for the cylinder, a valve chest, an

annular valve chamber in the valve chest' having curved seating surfaces, a supply passage in the valve chest conveying pressure fluid from a source of supply to the valve chamber, inlet passages leading from the curved seating surfaces to the cylinder, and

a valve in the form of an arcuate strip reciprocable in the valve chamber for controlling the inlet passages. v 2. In a. fluid actuated rock drill, the combination of a cylinder and a piston, an exhaust port for the cylinder, a valve chest, an annular valve chamber in the valve chest having opposed curved seating surfaces, a supply passage in the valve chest convey-- ing'pressure fluid from a source of supply to the valve chamber, inlet passages leading from the seating surfaces to the cylinder, and a plurality of arcuate valves reciprocable between the seating surfaces and cooperating therewith for controlling the inlet'passages.

3. In a fluid actuated rock drill, the combination of a cylinder and a piston, an exhaust port in the cylinder controlled by the g5 iston, a valve chest, an annular valve chamher in the valve chest having opposed curved seating surfaces, a supply passage in the valve chest constantly conveying pressure fluid from a source of supply to the valve cham- 0 her, inlet passages leading from the curved seating surfaces to the cylinder, an arcuate valve of uniform thickness throughout its length reciprocable transversely of the valve chamber and of less length than the valve chamber for controlling the inlet passages, and a pin in the valve chest extending through the valve for limiting endwise movement of the valve. 4. In a fluid actuated rock drill, the com- 40 bination of a cylinder and a piston, an exhaust port in the cylinder controlled by the piston, a valve chest in the cylinder comprising a pair of plates having cylindrical projections lying in the same transverse plane, said projections being spaced with respect to each other to form an annular valve chamber, a supply passage leading from, a source of pressure fluid supply to the valve chamber, inlet passages leading from opposite to sides or. the valve chamber to the cylinder,

opposed curved seating surfaces on the projections, a plurality of valves in the form of arcuate strips reciprocable transversely of the valve chamber and cooperating with the curved. surfaces to control the inlet passages, and pins in. the re ive chestextendin through the valves for limiting endwise movement of said valves in the valve chamber.

In testimony whereof I have signed this 6 specification.

' 5 WILLIAM A SMITH, J 

